The Trinity is the term employed to signify the central doctrine of the Christian religion — the truth that in the unity of the Godhead there are Three Persons, the Father, the Son, and the Holy Spirit, these Three Persons being truly distinct one from another. Thus, in the words of the Athanasian Creed: "the Father is God, the Son is God, and the Holy Spirit is God, and yet there are not three Gods but one God." In this Trinity of Persons the Son is begotten of the Father by an eternal generation, and the Holy Spirit proceeds by an eternal procession from the Father and the Son. Yet, notwithstanding this difference as to origin, the Persons are co-eternal and co-equal: all alike are uncreated and omnipotent. This, the Church teaches, is the revelation regarding God's nature which Jesus Christ, the Son of God, came upon earth to deliver to the world: and which she proposes to man as the foundation of her whole dogmatic system.

In Scripture there is as yet no single term by which the Three Divine Persons are denoted together. The word trias (of which the Latin trinitas is a translation) is first found in Theophilus of Antioch about A.D. 180. He speaks of "the Trinity of God [the Father], His Word and His Wisdom ("Ad. Autol.", II, 15). The term may, of course, have been in use before his time. Afterwards it appears in its Latin form of trinitas in Tertullian ("De pud." c. xxi). In the next century the word is in general use. It is found in many passages of Origen ("In Ps. xvii", 15). The first creed in which it appears is that of Origen's pupil, Gregory Thaumaturgus. In his Ekthesis tes pisteos composed between 260 and 270, he writes:

There is therefore nothing created, nothing subject to another in the Trinity: nor is there anything that has been added as though it once had not existed, but had entered afterwards: therefore the Father has never been without the Son, nor the Son without the Spirit: and this same Trinity is immutable and unalterable forever (P. G., X, 986).

It is manifest that a dogma so mysterious presupposes a Divine revelation. When the fact of revelation, understood in its full sense as the speech of God to man, is no longer admitted, the rejection of the doctrine follows as a necessary consequence. For this reason it has no place in the Liberal Protestantism of today. The writers of this school contend that the doctrine of the Trinity, as professed by the Church, is not contained in the New Testament, but that it was first formulated in the second century and received final approbation in the fourth, as the result of the Arian and Macedonian controversies. In view of this assertion it is necessary to consider in some detail the evidence afforded by Holy Scripture. Attempts have been made recently to apply the more extreme theories of comparative religion to the doctrine ot the Trinity, and to account for it by an imaginary law of nature compelling men to group the objects of their worship in threes. It seems needless to give more than a reference to these extravagant views, which serious thinkers of every school reject as destitute of foundation.

A. New Testament

The evidence from the Gospels culminates in the baptismal commission of Matthew 28:20. It is manifest from the narratives of the Evangelists that Christ only made the great truth known to the Twelve step by step. First He taught them to recognize in Himself the Eternal Son of God. When His ministry was drawing to a close, He promised that the Father would send another Divine Person, the Holy Spirit, in His place. Finally after His resurrection, He revealed the doctrine in explicit terms, bidding them "go and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost" (Matthew 28:18). The force of this passage is decisive. That "the Father" and "the Son" are distinct Persons follows from the terms themselves, which are mutually exclusive. The mention of the Holy Spirit in the same series, the names being connected one with the other by the conjunctions "and . . . and" is evidence that we have here a Third Person co-ordinate with the Father and the Son, and excludes altogether the supposition that the Apostles understood the Holy Spirit not as a distinct Person, but as God viewed in His action on creatures.

The phrase "in the name" (eis to onoma) affirms alike the Godhead of the Persons and their unity of nature. Among the Jews and in the Apostolic Church the Divine name was representative of God. He who had a right to use it was invested with vast authority: for he wielded the supernatural powers of Him whose name he employed. It is incredible that the phrase "in the name" should be here employed, were not all the Persons mentioned equally Divine. Moreover, the use of the singular, "name," and not the plural, shows that these Three Persons are that One Omnipotent God in whom the Apostles believed. Indeed the unity of God is so fundamental a tenet alike of the Hebrew and of the Christian religion, and is affirmed in such countless passages of the Old and New Testaments, that any explanation inconsistent with this doctrine would be altogether inadmissible.

The supernatural appearance at the baptism of Christ is often cited as an explicit revelation of Trinitarian doctrine, given at the very commencement of the Ministry. This, it seems to us, is a mistake. The Evangelists, it is true, see in it a manifestation of the Three Divine Persons. Yet, apart from Christ's subsequent teaching, the dogmatic meaning of the scene would hardly have been understood. Moreover, the Gospel narratives appear to signify that none but Christ and the Baptist were privileged to see the Mystic Dove, and hear the words attesting the Divine sonship of the Messias.

Besides these passages there are many others in the Gospels which refer to one or other of the Three Persons in particular and clearly express the separate personality and Divinity of each. In regard to the First Person it will not be necessary to give special citations: those which declare that Jesus Christ is God the Son, affirm thereby also the separate personality of the Father. The Divinity of Christ is amply attested not merely by St. John, but by the Synoptists. As this point is treated elsewhere (see JESUS CHRIST), it will be sufficient here to enumerate a few of the more important messages from the Synoptists, in which Christ bears witness to His Divine Nature.

He declares that He will come to be the judge of all men (Matthew 25:31). In Jewish theology the judgment of the world was a distinctively Divine, and not a Messianic, prerogative.

In the parable of the wicked husbandmen, He describes Himself as the son of the householder, while the Prophets, one and all, are represented as the servants (Matthew 21:33 sqq.).

He is the Lord of Angels, who execute His command (Matthew 24:31).

He approves the confession of Peter when he recognizes Him, not as Messias — a step long since taken by all the Apostles — but explicitly as the Son of God: and He declares the knowledge due to a special revelation from the Father (Matthew 16:16-17).

Finally, before Caiphas He not merely declares Himself to be the Messias, but in reply to a second and distinct question affirms His claim to be the Son of God. He is instantly declared by the high priest to be guilty of blasphemy, an offense which could not have been attached to the claim to be simply the Messias (Luke 22:66-71).

St. John's testimony is yet more explicit than that of the Synoptists. He expressly asserts that the very purpose of his Gospel is to establish the Divinity of Jesus Christ (John 20:31). In the prologue he identifies Him with the Word, the only-begotten of the Father, Who from all eternity exists with God, Who is God (John 1:1-18). The immanence of the Son in the Father and of the Father in the Son is declared in Christ's words to St. Philip: "Do you not believe, that I am in the Father, and the Father in Me?" (14:10), and in other passages no less explicit (14:7; 16:15; 17:21). The oneness of Their power and Their action is affirmed: "Whatever he [the Father] does, the Son also does in like manner" (5:19, cf. 10:38); and to the Son no less than to the Father belongs the Divine attribute of conferring life on whom He will (5:21). In 10:29, Christ expressly teaches His unity of essence with the Father: "That which my Father hath given me, is greater than all . . . I and the Father are one." The words, "That which my Father hath given me," can, having regard to the context, have no other meaning than the Divine Name, possessed in its fullness by the Son as by the Father.

Rationalist critics lay great stress upon the text: "The Father is greater than I" (14:28). They argue that this suffices to establish that the author of the Gospel held subordinationist views, and they expound in this sense certain texts in which the Son declares His dependence on the Father (5:19; 8:28). In point of fact the doctrine of the Incarnation involves that, in regard of His Human Nature, the Son should be less than the Father. No argument against Catholic doctrine can, therefore, be drawn from this text. So too, the passages referring to the dependence of the Son upon the Father do but express what is essential to Trinitarian dogma, namely, that the Father is the supreme source from Whom the Divine Nature and perfections flow to the Son. (On the essential difference between St. John's doctrine as to the Person of Christ and the Logos doctrine of the Alexandrine Philo, to which many Rationalists have attempted to trace it, see .)

In regard to the Third Person of the Blessed Trinity, the passages which can be cited from the Synoptists as attesting His distinct personality are few. The words of Gabriel (Luke 1:35), having regard to the use of the term, "the Spirit," in the Old Testament, to signify God as operative in His creatures, can hardly be said to contain a definite revelation of the doctrine. For the same reason it is dubious whether Christ's warning to the Pharisees as regards blasphemy against the Holy Spirit (Matthew 12:31) can be brought forward as proof. But in Luke 12:12, "The Holy Ghost shall teach you in the same hour what you must say" (Matthew 10:20, and Luke 24:49), His personality is clearly implied. These passages, taken in connection with Matthew 28:19, postulate the existence of such teaching as we find in the discourses in the Cenacle reported by St. John (14-16). We have in these chapters the necessary preparation for the baptismal commission. In them the Apostles are instructed not only as the personality of the Spirit, but as to His office towards the Church. His work is to teach whatsoever He shall hear (16:13) to bring back their minds the teaching of Christ (14:26), to convince the world of sin (16:8). It is evident that, were the Spirit not a Person, Christ could not have spoken of His presence with the Apostles as comparable to His own presence with them (14:16). Again, were He not a Divine Person it could not have been expedient for the Apostles that Christ should leave them, and the Paraclete take His place (16:7). Moreover, notwithstanding the neuter form of the word (pneuma), the pronoun used in His regard is the masculine ekeinos. The distinction of the Holy Spirit from the Father and from the Son is involved in the express statements that He proceeds from the Father and is sent by the Son (15:26; cf. 14:16, 26). Nevertheless, He is one with Them: His presence with the Disciples is at the same time the presence of the Son (14:17, 18), while the presence of the Son is the presence of the Father (14:23).

In the remaining New Testament writings numerous passages attest how clear and definite was the belief of the Apostolic Church in the three Divine Persons. In certain texts the coordination of Father, Son, and Spirit leaves no possible doubt as to the meaning of the writer. Thus in II Corinthians 13:13, St. Paul writes: "The grace of our Lord Jesus Christ, and the charity of God, and the communication of the Holy Ghost be with you all." Here the construction shows that the Apostle is speaking of three distinct Persons. Moreover, since the names and are alike Divine names, it follows that Jesus Christ is also regarded as a Divine Person. So also, in I Corinthians 12:4-11: "There are diversities of graces, but the same Spirit; and there are diversities of ministries, but the same Lord: and there are diversities of operations, but the same God, who worketh all [of them] in all [persons]." (Cf. also Ephesians 4:4-6; I Peter 1:2-3.)

But apart from passages such as these, where there is express mention of the Three Persons, the teaching of the New Testament regarding Christ and the Holy Spirit is free from all ambiguity. In regard to Christ, the Apostles employ modes of speech which, to men brought up in the Hebrew faith, necessarily signified belief in His Divinity. Such, for instance, is the use of the Doxology in reference to Him. The Doxology, "To Him be glory for ever and ever" (cf. I Chronicles 16:38; 29:11; Psalm 103:31; 28:2), is an expression of praise offered to God alone. In the New Testament we find it addressed not alone to God the Father, but to Jesus Christ (II Timothy 4:18; II Peter 3:18; Revelations 1:6; Hebrews 13:20-21), and to God the Father and Christ in conjunction (Revelations 5:13, 7:10). Not less convincing is the use of the title Lord (Kyrios). This term represents the Hebrew Adonai, just as (Theos) represents Elohim. The two are equally Divine names (cf. I Corinthians 8:4). In the Apostolic writings Theos may almost be said to be treated as a proper name of God the Father, and Kyrios of the Son (see, for example, I Corinthians 12:5-6); in only a few passages do we find Kyrios used of the Father (I Corinthians 3:5; 7:17) or Theos of Christ. The Apostles from time to time apply to Christ passages of the Old Testament in which Kyrios is used, for example, I Corinthians 10:9 (Numbers 21:7), Hebrews 1:10-12 (Psalm 101:26-28); and they use such expressions as "the fear of the Lord" (Acts 9:31; II Corinthians 5:11; Ephesians 5:21), "call upon the name of the Lord," indifferently of God the Father and of Christ (Acts 2:21; 9:14; Romans 10:13). The profession that "Jesus is the Lord" (Kyrion Iesoun, Romans 10:9; Kyrios Iesous, I Corinthians 12:3) is the acknowledgment of Jesus as Jahweh. The texts in which St. Paul affirms that in Christ dwells the plenitude of the Godhead (Colossians 2:9), that before His Incarnation He possessed the essential nature of God (Philemon 2:6), that He "is over all things, God blessed for ever" (Romans 9:5) tell us nothing that is not implied in many other passages of his Epistles.

The doctrine as to the Holy Spirit is equally clear. That His distinct personality was fully recognized is shown by many passages. Thus He reveals His commands to the Church's ministers: "As they were ministering to the Lord and fasting, the Holy Ghost said to them: Separate me Saul and Barnabas . . ." (Acts 13:2). He directs the missionary journey of the Apostles: "They attempted to go into Bithynia, and the Spirit of Jesus suffered them not" (Acts 16:7; cf. Acts 5:3; 15:28; Romans 15:30). Divine attributes are affirmed of Him.

He possesses omniscience and reveals to the Church mysteries known only to God (I Corinthians 2:10);

it is He who distributes charismata (I Cor., 12:11);

He is the giver of supernatural life (II Cor., 3:8);

He dwells in the Church and in the souls of individual men, as in His temple (Romans 8:9-11; I Corinthians 3:16, 6:19).

The work of justification and sanctification is attributed to Him (I Cor., 6:11; Rom., 15:16), just as in other passages the same operations are attributed to Christ (I Cor., 1:2; Gal., 2:17).

To sum up: the various elements of the Trinitarian doctrine are all expressly taught in the New Testament. The Divinity of the Three Persons is asserted or implied in passages too numerous to count. The unity of essence is not merely postulated by the strict monotheism of men nurtured in the religion of Israel, to whom "subordinate deities" would have been unthinkable; but it is, as we have seen, involved in the baptismal commission of Matthew 28:19, and, in regard to the Father and the Son, expressly asserted in John 10:38. That the Persons are co-eternal and coequal is a mere corollary from this. In regard to the Divine processions, the doctrine of the first procession is contained in the very terms Father and Son: the procession of the Holy Spirit from the Father and Son is taught in the discourse of the Lord reported by St. John (14-17) (see ).

B. Old Testament

The early Fathers were persuaded that indications of the doctrine of the Trinity must exist in the Old Testament and they found such indications in not a few passages. Many of them not merely believed that the Prophets had testified of it, they held that it had been made known even to the Patriarchs. They regarded it as certain that the Divine messenger of Genesis 16:7, 18, 21:17, 31:11; Exodus 3:2, was God the Son; for reasons to be mentioned below (III. B.) they considered it evident that God the Father could not have thus manifested Himself (cf. Justin, "Dial.", 60; Irenaeus, "Adv. haer.", IV, xx, 7-11; Tertullian, "Adv. Prax.", 15-16; Theoph., "Ad Autol.", ii, 22; Novat., "De Trin.", 18, 25, etc.). They held that, when the inspired writers speak of "the Spirit of the Lord", the reference was to the Third Person of the Trinity: and one or two (Irenaeus, "Adv. haer.", II, xxx, 9; Theophilus, "Ad. Aut.", II, 15; Hippolytus, "Con. Noet.", 10) interpret the hypostatic Wisdom of the Sapiential books, not, with St. Paul, of the Son (Hebrews 1:3; cf. Wisdom, vii, 25, 26), but of the Holy Spirit. But in others of the Fathers is found what would appear to be the sounder view, that no distinct intimation of the doctrine was given under the Old Covenant. (Cf. Gregory Nazianzen, "Or. theol.", v, 26; Epiphanius, "Ancor." 73, "Haer.", 74; Basil, "Adv. Eunom.", II, 22; Cyril Alex., "In Joan.", xii, 20.)

Some of these, however, admitted that a knowledge of the mystery was granted to the Prophets and saints of the Old Dispensation (Epiph., "Haer.", viii, 5; Cyril Alex., "Con. Julian.," I). It may be readily conceded that the way is prepared for the revelation in some of the prophecies. The names Emmanuel (Isaias 7:14) and God the Mighty (Isaias 9:6) affirmed of the Messias make mention of the Divine Nature of the promised deliverer. Yet it seems that the Gospel revelation was needed to render the full meaning of the passages clear. Even these exalted titles did not lead the Jews to recognize that the Saviour to come was to be none other than God Himself. The Septuagint translators do not even venture to render the words God the Mighty literally, but give us, in their place,"the angel of great counsel." A still higher stage of preparation is found in the doctrine of the Sapiential books regarding the Divine Wisdom. In Proverbs 8, Wisdom appears personified, and in a manner which suggests that the sacred author was not employing a mere metaphor, but had before his mind a real person (cf. verses 22, 23). Similar teaching occurs in Ecclus., 24, in a discourse which Wisdom is declared to utter in "the assembly of the Most High", i. e. in the presence of the angels. This phrase certainly supposes Wisdom to be conceived as person. The nature of the personality is left obscure; but we are told thnt the whole earth is Wisdom's Kingdom, that she finds her delight in all the works of God, but that Israel is in a special manner her portion and her inheritance (Ecclus., 24:8-13).

In the Book of the Wisdom of Solomon we find a still further advance. Here Wisdom is clearly distinguished from Jehovah: "She is. . .a certain pure emanation of the glory of the almighty God. . .the brightness of eternal light, and the unspotted mirror of God's majesty, and the image of his goodness" (Wisdom 7:25-26. Cf. Hebrews 1:3). She is, moreover, described as "the worker of all things" (panton technitis, 7:21), an expression indicating that the creation is in some manner attributable to her. Yet in later Judaism this exalted doctrine suffered eclipse, and seems to have passed into oblivion. Nor indeed can it be said that the passage, even though it manifests some knowledge of a second personality in the Godhead, constitutes a revelation of the Trinity. For nowhere in the Old Testament do we find any clear indication of a Third Person. Mention is often made of the Spirit of the Lord, but there is nothing to show that the Spirit was viewed as distinct from Jahweh Himself. The term is always employed to signify God considered in His working, whether in the universe or in the soul of man. The matter seems to be correctly summed up by Epiphanius, when he says: "The One Godhead is above all declared by Moses, and the twofold personality (of Father and Son) is strenuously asuerted by the Prophets. The Trinity is made known by the Gospel" ("Haer.", Ixxiv).

A. The Church Fathers

In this section we shall show that the doctrine of the Blessed Trinity has from the earliest times been taught by the Catholic Church and professed by her members. As none deny this for any period subsequent to the Arian and Macedonian controversies, it will be sufficient if we here consider the faith of the first four centuries only. An argument of very great weight is provided in the liturgical forms of the Church. The highest probative force must necessarily attach to these, since they express not the private opinion of a single individual, but the public belief of the whole body of the faithful. Nor can it be objected that the notions of Christians on the subject were vague and confused, and that their liturgical forms reflect this frame of mind. On such a point vagueness was impossible. Any Christian might be called on to seal with his blood his belief that there is but One God. The answer of Saint Maximus (c. A.D. 250) to the command of the proconsul that he should sacrifice to the gods, "I offer no sacrifice save to the One True God," is typical of many such replies in the Acts of the martyrs. It is out of the question to suppose that men who were prepared to give their lives on behalf of this fundamental truth were in point of fact in so great confusion in regard to it that they were unaware whether their creed was monotheistic, ditheistic, or tritheistic. Moreover, we know that their instruction regarding the doctrines of their religion was solid. The writers of that age bear witness that even the unlettered were thoroughly familiar with the truths of faith (cf. Justin, "Apol.", I, 60; Irenaeus, "Adv. haer.", III, iv, n. 2).

(1) Baptismal formulas

We may notice first the baptismal formula, which all acknowledge to be primitive. It has already been shown that the words as prescribed by Christ (Matthew 28:19) clearly express the Godhead of the Three Persons as well as their distinction, but another consideration may here be added. Baptism, with its formal renunciation of Satan and his works, was understood to be the rejection of the idolatry of paganism and the solemn consecration of the baptised to the one true God (Tert., "De spect.", iv; Justin, "Apol.", I, iv). The act of consecration was the invocation over them of the Father, Son, and Holy Spirit. The supposition that they regarded the Second and Third Persons as created beings, and were in fact consecrating themselves to the service of creatures, is manifestly absurd. St. Hippolytus has expressed the faith of the Church in the clearest terms: "He who descends into this laver of regeneration with faith forsakes the Evil One and engages himself to Christ, renounces the enemy and confesses that Christ is God . . . he returns from the font a son of God and a coheir of Christ. To Whom with the all holy, the good and lifegiving Spirit be glory now and always, forever and ever. Amen" ("Serm. in Theoph.", n. 10).

The doxologies

(2) The witness of the doxologies is no less striking. The form now universal, "Glory be to the Father, and to the Son, and to the Holy Ghost," so clearly expresses the Trinitarian dogma that the Arians found it necessary to deny that it had been in use previous to the time of Flavian of Antioch (Philostorgius, "Hist. eccl.", III, xiii). It is true that up to the period of the Arian controversy another form, "Glory to the Father, through the Son, in the Holy Spirit," had been more common (cf. I Clement, 58, 59; Justin, "Apol.", I, 67). This latter form is indeed perfectly consistent with Trinitarian belief: it, however, expresses not the coequality of the Three Persons, but their operation in regard to man. We live in the Spirit, and through Him we are made partakers in Christ (Galatians 5:25; Romans 8:9); and it is through Christ, as His members, that we are worthy to offer praise to God (Heb. 13:15). But there are many passages in the ante-Nicene Fathers which show that the form, "Glory be to the Father and to the Son, and to [with] the Holy Spirit," was also in use.

In the narrative of St. Polycarp's martyrdom we read: "With Whom to Thee and the Holy Spirit be glory now and for the ages to come" (Mart. S. Polyc., n.14; cf. n. 22).

Clement of Alexandria bids men "give thanks and praise to the only Father and Son, to the Son and Father with the Holy Spirit" (Paed., III, xii).

St. Hippolytus closes his work against Noetus with the words: "To Him be glory and power with the Father and the Holy Spirit in Holy Church now and always for ever and ever. Amen" (Contra Noet., n. 18).

Denis of Alexandria uses almost the same words: "To God the Father and to His Son Jesus Christ with the Holy Spirit be honour and glory forever and ever, Amen" (in St. Basil, "De Spiritu Sancto", xxix, n. 72).

St. Basil further tells us that it was an immemorial custom among Christians when they lit the evening lamp to give thanks to God with prayer: Ainoumen Patera kai Gion kai Hagion Pneuma Theou ("We praise the Father, and the Son, and the Holy Spirit of God").

(3) Other patristic writings

The doctrine of the Trinity is formally taught in every class of ecclesiastical writing. From among the apologists we may note Justin, "Apol." I, vi; Athenagoras, "Legat: pro Christ.", n. 12. The latter tells us that Christians "are conducted to the future life by this one thing alone, that they know God and His Logos, what is the oneness of the Son with the Father, what the communion of the Father with the Son, what is the Spirit, what is the unity of these three, the Spirit, the Son, and the Father, and their distinction in unity." It would be impossible to be more explicit. And we may be sure that an apologist, writing for pagans, would weigh well the words in which he dealt with this doctrine. Amongst polemical writers we may refer to Irenaeus, "Adv. haer.", I, xxii, IV, xx, 1-6. In these passages he rejects the Gnostic figment that the world was created by aeons who had emanated from God, but were not consubstantial with Him, and teaches the consubstantiality of the Word and the Spirit by Whom God created all things. Clement of Alexandria professes the doctrine in "Paedag." I, vi, and somewhat later Gregory Thaumaturgus, as we have already seen, lays it down in the most express terms in his creed (P.G., X, 986).

(4) As contrasted with heretical teachings

Yet further evidence regarding the Church's doctrine is furnished by a comparison of her teaching with that of heretical sects. The controversy with the Sabellians in the third century proves conclusively that she would tolerate no deviation from Trinitarian doctrine. Noetus of Smyrna, the originator of the error, was condemned by a local synod, about A.D. 200. Sabellius, who propagated the same heresy at Rome c. A.D. 220, was excommunicated by St. Callistus. It is notorious that the sect made no appeal to tradition: it found Trinitarianism in possession wherever it appeared — at Smyrna, at Rome, in Africa, in Egypt. On the other hand, St. Hippolytus, who combats it in the "Contra Noetum," claims Apostolic tradition for the doctrine of the Catholic Church: "Let us believe, beloved brethren, in accordance with the tradition of the Apostles, that God the Word came down from heaven to the holy Virgin Mary to save man." Somewhat later (c. A.D. 260) Denis of Alexandria found that the error was widespread in the Libyan Pentapolis, and he addressed a dogmatic letter against it to two bishops, Euphranor and Ammonius. In this, in order to emphasize the distinction between the Persons, he termed the Son poiema tou Theou and used other expressions capable of suggesting that the Son is to be reckoned among creatures. He was accused of heterodoxy to St. Dionysius of Rome, who held a council and addressed to him a letter dealing with the true Catholic doctrine on the point in question. The Bishop of Alexandria replied with a defense of his orthodoxy entitled "Elegxhos kai apologia," in whioh he corrected whatever had been erroneous. He expressly professes his belief in the consubstantiality of the Son, using the very term, , which afterwards became the touchstone of orthodoxy at Nicaea (P. G., XXV, 505). The story of the controversy is conclusive as to the doctrinal standard of the Church. It shows us that she was firm in rejecting on the one hand any confusion of the Persons and on the other hand any denial of their consubstantiality.

The information we possess regarding another heresy — that of Montanus — supplies us with further proof that the doctrine of the Trinity was the Church's teaching in A.D. 150. Tertullian affirms in the clearest terms that what he held as to the Trinity when a Catholic he still holds as a Montanist ("Adv. Prax.", II, 156); and in the same work he explicitly teaches the Divinity of the Three Persons, their distinction, the eternity of God the Son (op. cit., xxvii). Epiphanius in the same way asserts the orthodoxy of the Montanists on this subject (Haer., lxviii). Now it is not to be supposed that the Montanists had accepted any novel teaching from the Catholic Church since their secession in the middle of the second century. Hence, inasmuch as there was full agreement between the two bodies in regard to the Trinity, we have here again a clear proof that Trinitarianism was an article of faith at a time when the Apostolic tradition was far too recent for any error to have arisen on apoint so vital.

B. Later Controversy

Notwithstanding the force of the arguments we have just summarised, a vigorous controversy has been carried on from the end of the seventeenth century to the present day regarding the Trinitarian doctrine of the ante-Nicene Fathers. The Socinian writers of the seventeenth century (e. g. Sand, "Nucleus historiae ecclesiastic", Amsterdam, 1668) asserted that the language of the early Fathers in many passages of their works shows that they agreed not with Athanasius, but with Arius. Petavius, who was at that period engaged on his great theological work, was convinced by their arguments, and allowed that at least some of these Fathers had fallen into grave errors. On the other hand, their orthodoxy was vigorously defended by the Anglican divine Dr. George Bull ("Defensio Fidei Nicaean", Oxford, 1685) and subsequently by Bossuet, Thomassinus, and other Catholic theologians. Those who take the less favourable view assert that they teach the following points inconsistent with the post-Nicene belief of the Church:

That the Son even as regards His Divine Nature is inferior and not equal to the Father;

that the Son alone appeared in the theophanies of the Old Testament, inasmuchas the Father is essentially invisible, the Son, however, not so;

that the Son is a created being;

that the generation of the Son is not eternal, but took place in time.

We shall examine these four points in order. (1) In proof of the assertion that many of the Fathers deny the equality of the Son with the Father, passages are cited from Justin (Apol., I, xiii, xxxii), Irenaeus (Adv. haer., III, viii, n. 3), Clem. Alex. ("Strom." VII, ii), Hippolytus (Con. Noet., n. 14), Origen (Con. Cels., VIII, xv). Thus Irenaeus (loc. cit.) says: "He commanded, and they were created . . . Whom did He command? His Word, by whom, says the Scripture, the heavens were established. And Origen, loc. cit., says: "We declare that the Son is not mightier than the Father, but inferior to Him. And this belief we ground on the saying of Jesus Himself: "The Father who sent me is greater than I." Now in regard to these passages it must be borne in mind that there are two ways of considering the Trinity. We may view the Three Persons insofar as they are equally possessed of the Divine Nature or we may consider the Son and the Spirit as derivlng from the Father, Who is the sole source of Godhead, and from Whom They receive all They have and are. The former mode of considering them has been the more common since the Arian heresy. The latter, however, was more frequent previously to that period. Under this aspect, the Father, as being: the sole source of all, may be termed greater than the Son. Thus Athanasius, Basil, Gregory Nazianzen, Gregory of Nyssa, and the Fathers of the Council of Sardica, in their synodical letter, all treat our Lord's words, teaches "The Father is greater than I" as having reference to His Godhead (cf. Petavius, "De Trin.", II, ii, 7, vi, 11). From this point of view it may be said that in the creation of the world the Father commanded, the Son obeyed. The expression is not one which would have been employed by Latin writers who insist thst creation and all God's works proceed from Him as One and not from the Persons as distinct from each other. But this truth was unfamiliar to the early Fathers.

(2) Justin (Dial., n. 60) Irenaeus (Adv. haer., IV, xx, nn. 7, 11), Tertullian ("C. Marc.", II, 27; "Adv. Prax.", 15, 16), Novatian (De Trin., xviii, 25), Theophilus (Ad Autol., II, xxii), are accused of teaching that the theophanies were incompatible with the essential nature of the Father, yet not incompatible with that of the Son. In this case also the difficulty is largely removed if it be remembered that these writers regarded all the Divine operations as proceeding from the Three Persons as such, and not from the Godhead viewed as one. Now Revelation teaches us that in the work of the creation and redemption of the world the Father effects His purpose through the Son. Through Him He made the world; through Him He redeemed it; through Him He will judge it. Hence it was believed by these writers that, having regard to the present disposition of Providence, the theophanies could only have been the work of the Son. Moreover, in Colossians 1:15, the Son is expressly termed "the image of the invisible God" (eikon tou Theou rou aoratou). This expression they seem to have taken with strict literalness. The function of an eikon is to manifest what is itself hidden (cf. St. John Damascene, "De imagin.", III, n. 17). Hence they held that the work of revealing the Father belongs by nature to the Second Person of the Trinity, and concluded that the theophanies were His work.

(3) Expressions which appear to contain the statement that the Son was created are found in Clement of Alexandria (Strom., V, xiv; VI, vii), Tatian (Orat., v), Tertullian ("Adv. Prax." vi; "Adv. "Adv. Hermong.", xviii, xx), Origen (In Joan., I, n. 22). Clement speaks of Wisdom as "created before all things" (protoktistos), and Tatian terms the Word the "first-begotten work of (ergon prototokon) Of the Father. Yet the meaning of these authors is clear. In Colossians 1:16, St. Paul says that all things were created in the Son. This was understood to signify that creation took place according to exemplar ideas predetermined by God and existing in the Word. In view of this, it might be said that the Father created the Word, this term being used in place of the more accurate generated, inasmuch as the exemplar ideas of creation were communicated by the Father to the Son. Or, again, the actual Creation of the world might be termed the creation of the Word, since it takes place according to the ideas which exist in the Word. The context invariably shows that the passage is to be understood in one or another of these senses. The expression is undoubtedly very harsh, and it certainly would never have been employed but for the verse, Proverbs 8:22, which is rendered in the Septuagint and the old Latin versions, "The Lord created (ektise) me, who am the beginning of His ways." As the passage was understood as having reference to the Son, it gave rise to the question how it could be said that Wisdom was created (Origen, "Princ.", I, ii, n. 3). It is further to be remembered that accurate terminology in regard to the relations between the Three Persons was the fruit of the controversies which sprang up in the fourth century. The writers of an earlier period were not concerned with Arianism, and employed expressions which in the light of subsequent errors are seen to be not merely inaccurate, but dangerous. (4) Greater difficulty is perhaps presented by a series of passages which appear to assert that prior to the Creation of the world the Word was not a distinct hypostasis from the Father. These are found in Justin (C. Tryphon., lxi), Tatian (Con. Graecos, v), Athenagoras (Legat., x), Theophilus (Ad Autol., II, x, 22); Hippolytus (Con. Noet., x); Tertullian ("Adv. Prax.", v-vii; "Adv. Hermogenem" xviii). Thus Theophilus writes (op. cit., n. 22): "What else is this voice [heard in Paradise] but the Word of God Who is also His Son? . . . For before anything came into being, He had Him as a counsellor, being His own mind and thought [i.e. as the logos endiathetos, c. x]). But when God wished to make all that He had determined on, then did He beget Him as the uttered Word [logos prophorikos], the firstborn of all creation, not, however, Himself being left without Reason (logos), but having begotten Reason, and ever holding converse with Reason." Expressions such as these are undoubtedly due to the influence of the Stoic philosophy: the logos endiathetos and logos prophorikos were current conceptions of that school. It is evident that these apologists were seeking to explain the Christian Faith to their pagan readers in terms with which the latter were familiar. Some Catholic writers have indeed thought that the influence of their previous training did lead some of them into Subordinationism, although the Church herself was never involved in the error (see ). Yet it does not seem necessary to adopt this conclusion. If the point of view of the writers be borne in mind, the expressions, strange as they are, will be seen not to be incompatibIe with orthodox belief. The early Fathers, as we have said, regarded Proverbs 8:22, and Colossians 1:15, as distinctly teaching that there is a sense in which the Word, begotten before all worlds, may rightly be said to have been begotten also in time. This temporal generation they conceived to be none other than the act of creation. They viewed this as the complement of the eternal generation, inasmuch as it is the external manifestation of those creative ideas which from all eternity the Father has communicated to the Eternal Word. Since, in the very same works which contain these perplexing expressions, other passages are found teaching explicitly the eternity of the Son, it appears most natural to interpret them in this sense. It should further be remembered that throughout this period theologians, when treating of the relation of the Divine Persons to each other, invariably regard them in connection with the cosmogony. Only later, in the Nicene epoch, did they learn to prescind from the question of creation and deal with the threefold Personality exclusively from the point of view of the Divine life of the Godhead. When that stage was reached expressions such as these became impossible.

The Vatican Council has explained the meaning to be attributed to the term mystery in theology. It lays down that a mystery is a truth which we are not merely incapable of discovering apart from Divine Revelation, but which, even when revealed, remains "hidden by the veil of faith and enveloped, so to speak, by a kind of darkness" (Const., "De fide. cath.", iv). In other words, our understanding of it remains only partial, even after we have accepted it as part of the Divine messege. Through analogies and types we can form a representative concept expressive of what is revealed, but we cannot attain that fuller knowledge which supposes that the various elements of the concept are clearly grasped and their reciprocal compatibility manifest. As regards the vindication of a mystery, the office of the natural reason is solely to show that it contains no intrinsic impossibility, that any objection urged against it on Reason. "Expressions such as these are undoubtedly the score that it violates the laws of thought is invalid. More than this it cannot do.

The Vatican Council further defined that the Christian Faith contains mysteries strictly so called (can. 4). All theologians admit that the doctrine of the Trinity is of the number of these. Indeed, of all revealed truths this is the most impenetrable to reason. Hence, to declare this to be no mystery would be a virtual denial of the canon in question. Moreover, our Lord's words, Matthew 11:27, "No one knoweth the Son, but the Father," seem to declare expressly that the plurality of Persons in the Godhead is a truth entirely beyond the scope of any created intellect. The Fathers supply many passages in which the incomprehensibility of the Divine Nature is affirmed. St. Jerome says, in a well-known phrase: "The true profession of the mystery of the Trinity is to own that we do not comprehend it" (De mysterio Trinitatus recta confessio est ignoratio scientiae — "Proem ad 1. xviii in Isai."). The controversy with the Eunomians, who declared that the Divine Essence was fully expressed in the absolutely simple notion of "the Innascible" (agennetos), and that this was fully comprehensible by the human mind, led many of the Greek Fathers to insist on the incomprehensibility of the Divine Nature, more especially in regard to the internal processions. St. Basil. "In Eunom.", I, n. 14; St. Cyril of Jerusdem, "Cat.", VI; St. John Damascene, "Fid. Orth.", I, ii, etc., etc.).

At a later date, however, some famous names are to be found defending a contrary opinion Anselm ("Monol.", 64), Abelard ("ln Ep. ad Rom."), Hugo of St. Victor ("De sacram." III, xi), and Richard of St. Victor ("De Trin.", III, v) all declare that it is possible to assign peremptory reasons why God should be both One and Three. In explanation of this it should be noted that at that period the relation of philosophy to revealed doctrine was but obscurely understood. Only after the Aristotelean system had obtained recognition from theologians was this question thoroughly treated. In the intellectual ferment of the time Abelard initiated a Rationalistic tendency: not merely did he claim a knowledge of the Trinity for the pagan philosophers, but his own Trinitarian doctrine was practically Sabellian. Anselm's error was due not to Rationalism, but to too wide an application of the Augustinian principle "Crede ut intelligas". Hugh and Richard of St. Victor were, however, certainly influenced by Abelard's teaching. Raymond Lully's (1235-1315) errors in this regard were even more extreme. They were expressly condemned by Gregory XI in 1376. In the nineteenth century the influence of the prevailing Rationalism manifested itself in several Catholic writers. Frohschammer and Günther both asserted that the dogma of the Trinity was capable of proof. Pius IX reprobated their opinions on more than one occasion (Denzinger, 1655 sq., 1666 sq., 1709 sq.), and it was to guard against this tendency that the Vatican Council issued the decrees to which reference has been made. A somewhat similar, though less aggravated, error on the part of Rosmini was condemned, 14 December, 1887 (Denz., 1915).

A. Nature and Personality

The Greek Fathers approached the problem of Trinitarian doctrine in a way which differs in an important particular from that which, since the days of St. Augustine, has become traditional in Latin theology. In Latin theology thought fixed first on the Nature and only subsequently on the Persons. Personality is viewed as being, so to speak, the final complement of the Nature: the Nature is regarded as logically prior to the Personality. Hence, because God's Nature is one, He is known to us as One God before He can be known as Three Persons. And when theologians speak of God without special mention of a Person, conceive Him under this aspect. This is entirely different from the Greek point of view. Greek thought fixed primarily on the Three distinct Persons: the Father, to Whom, as the source and origin of all, the name of God (Theos) more especially belongs; the Son, proceeding from the Father by an eternal generation, and therefore rightly termed God also; and the Divine Spirit, proceeding from the Father through the Son. The Personality is treated as logically prior to the Nature. Just as human nature is something which the individual men possesses, and which can only be conceived as belonging to and dependent on the individual, so the Divine Nature is something which belongs to the Persons and cannot be conceived independently of Them.

The contrast appears strikingly in regard to the question of creation. All Western theologians teach that creation, like all God's external works, proceeds from Him as One: the separate Personalities do not enter into consideration. The Greeks invariably speak as though, in all the Divine works, each Person exercises a separate office. Irenaeus replies to the Gnostics, who held that the world was created by a demiurge other than the supreme God, by affirming that God is the one Creator, and that He made all things by His Word and His Wisdom, the Son and the Spirit (Adv. haer., I, xxii; II, iv, 4, 5, xxx, 9; IV, xx, 1). A formula often found among the Greek Fathers is that all things are from the Father and are effected by the Son in the Spirit (Athanasius, "Ad Serap.", I, xxxi; Basil, "De Spiritu Sancto", n. 38; Cyril of Alexandria, "De Trin. dial.", VI). Thus, too, Hippolytus (Con Noet., x) says that God has fashioned all things by His Word and His Wisdom creating them by His Word, adorning them by His Wisdom (gar ta genomena dia Logou kai Sophias technazetai, Logo men ktizon Sophia de kosmon). The Nicene Creed still preserves for us this point of view. In it we still profess our belief "in one God the Father Almighty, Creator of heaven and earth . . . and in one Lord Jesus Christ . . . by Whom all things were made . . . and in the Holy Ghost."

B. The Divine Unity

The Greek Fathers did not neglect to safeguard the doctrine of the Divine Unity, though manifestly their standpoint requires a different treatment from that employed in the West. The consubstantiality of the Persons is asserted by St. Irenaeus when he tells us that God created the world by His Son and His Spirit, "His two hands" (Adv. haer., IV, xx, 1). The purport of the phrase is evidently to indicate that the Second and Third Persons are not substantially distinct from the First. A more philosophical description is the doctrine of the Recapitulation (sygkephalaiosis). This seems to be first found in the correspondence between St. Denis of Alexandria and St. Dionysius of Rome. The former writes: "We thus [i.e., by the twofold procession] extend the Monad [the First Person] to the Trinity, without causing any division, and were capitulate the Trinity in the Monad without causing diminution" (outo men emeis eis te ten Triada ten Monada, platynomen adiaireton, kai ten Triada palin ameioton eis ten Monada sygkephalaioumetha — P.G., XXV, 504). Here the consubstantiality is affirmed on the ground that the Son and Spirit, proceeding from the Father, are nevertheless not separated from Him; while they again, with all their perfections, can be regarded as contained within Him.

This doctrine supposes a point of view very different from that with which we are now familiar. The Greek Fathers regarded the Son as the Wisdom and power of the Father (I Cor., 1:24) in a formal sense, and in like manner, the Spirit as His Sanctity. Apart from the Son the Father would be without Hls Wisdom; apart from the Spirit He would be without His Sanctity. Thus the Son and the Spirit are termed "Powers" (Dynameis) of the Father. But while in creatures the powers and faculties are mere accidental perfections, in the Godhead they are subsistent hypostases. Denis of Alexandria regarding the Second and Third Persons as the Father's "Powers", speaks of the First Person as being "extended" to them, and not divided from them. And, since whatever they have and are flows from Him, this writer asserts that if we fix our thoughts on the sole source of Deity alone, we find in Him undiminished all that is contained in them.

The Arian controversy led to insistence on the Homoüsia. But with the Greeks this is not a starting point, but a conclusion, the result of reflective analysis. The sonship of the Second Person implies that He has received the Divine Nature in its fullness, for all generation implies the origination of one who is like in nature to the originating principle. But here, mere specific unity is out of the question. The Divine Essence is not capable of numerical multiplication; it is therefore, they reasoned, identically the same nature which both possess. A similar line of argument establishes that the Divine Nature as communicated to the Holy Spirit is not specifically, but numerically, one with that of the Father and the Son. Unity of nature was understood by the Greek Fathers as involving unity of will and unity of action (energeia). This they declared the Three Persons to possess (Athanasius, "Adv. Sabell.", xii, 13; Basil, "Ep. clxxxix," n. 7; Gregory of Nyssa, "De orat. dom.," John Damascene, "De fide orth.", III, xiv). Here we see an important advance in the theology of the Godhead. For, as we have noted, the earlier Fathers invariably conceive the Three Persons as each exercising a distinct and separate function.

Finally we have the doctrine of Circuminsession (perichoresis). By this is signified the reciprocal inexistence and compenetration of the Three Persons. The term perichoresis is first used by St. John Damascene. Yet the doctrine is found much earlier. Thus St. Cyril of Alexandria says that the Son is called the Word and Wisdom of the Father "because of the reciprocal inherence of these and the mind" (dia ten eis allela . . . ., hos an eipoi tis, antembolen). St. John Damascene assigns a twofold basis for this inexistence of the Persons. In some passages he explains it by the doctrine already mentioned, that the Son and the Spirit are dynameis of the Father (cf. "De recta sententia"). Thus understood, the Circuminsession is a corollary of the doctrine of Recapitulation. He also understands it as signifying the identity of essence, will, and action in the Persons. Wherever these are peculiar to the individual, as is the case in all creatures, there, he tells us, we have separate existence (kechorismenos einai). In the Godhead the essence, will, and action are but one. Hence we have not separate existence, but Circuminsession (perichoresis) (Fid. orth., I, viii). Here, then, the Circuminsession has its basis in the Homoüsia.

It is easy to see that the Greek system was less well adapted to meet the cavils of the Arian and Macedonian heretics than was that subsequently developedby St. Augustine. Indeed the controversies of the fourth century brought some of the Greek Fathers notably nearer to the positions of Latin theology. We have seen that they were led to affirm the action of the Three Persons to be but one. Didymus even employs expressions which seem to show that he, like the Latins, conceived the Nature as logically antecedent to the Persons. He understands the term God as signifying the whole Trinity, and not, as do the other Greeks, the Father alone: "When we pray, whether we say 'Kyrie eleison', or 'O God aid us', we do not miss our mark: for we include the whole of the Blessed Trinity in one Godhead" (De Trin., II, xix).

C. Mediate and Immediate Procession

The doctrine that the Spirit is the image of the Son, as the Son is the image of the Father, is characteristic of Greek theology. It is asserted by St. Gregory Thaumaturgus in his Creed. It is assumed by St. Athanasius as an indisputable premise in his controversy with the Macedonians (Ad Serap., I, xx, xxi, xxiv; II, i, iv). It is implied in the comparisons employed both by him (Ad Serap. I, xix) and by St. Gregory Nazianzen (Orat. xxxi, 31, 32), of the Three Divine Persons to the sun, the ray, the light; and to the source, the spring, and the stream. We find it also in St. Cyril of Alexandria ("Thesaurus assert.", 33), St. John Damascene ("Fid.orth." I, 13), etc. This supposes that the procession of the Son from the Father is immediate; that of the Spirit from the Father is mediate. He proceeds from the Father through the Son. Bessarion rightly observes that the Fathers who used these expressions conceived the Divine Procession as taking place, so to speak, along a straight line (P. G., CLXI, 224). On the other hand, in Western theology the symbolic diagram of the Trinity has ever been the triangle, the relations of the Three Persons one to another being precisely similar. The point is worth noting, for this diversity of symbolic representation leads inevitably to very different expressions of the same dogmatic truth. It is plain that these Fathers would have rejected no less firmly than the Latins the later Photian heresy that the Holy Spirit proceeds from the Father alone. (For this question the reader is referred to .)

D. The Son

The Greek theology of the Divine Generation differs in certain particulars from the Latin. Most Western theologians base their theory on the name, Logos, given by St. John to the Second Person. This they understand in the sense of "concept" (verbum mentale), and hold that the Divine Generation is analogous to the act by which the created intellect produces its concept. Among Greek writers this explanation is unknown. They declare the manner of the Divine Generation to be altogether beyond our comprehension. We know by revelation that God has a Son; and various other terms besides Son employed regarding Him in Scripture, such as Word, Brightness of His glory, etc., show us that His sonship must be conceived as free from any relation. More we know not (cf. Gregory Nazianzen, "Orat. xxix", p. 8, Cyril of Jerusalem, "Cat.", xi, 19; John Damascene, "Fid. orth.", I, viii). One explanation only can be given, namely, that the perfection we call fecundity must needs be found in God the Absolutely Perfect (St. John Damascene, "Fid.orth.", I, viii). Indeed it would seem that the great majority of the Greek Fathers understood logos not of the mental thought; but of the uttered word ("Dion. Alex."; Athanasius, ibid.; Cyril of Alexandria, "De Trin.", II). They did not see in the term a revelation that the Son is begotten by way of intellectual procession, but viewed it as a metaphor intended to exclude the material associations of human sonship (Gregory of Nyssa, "C. Eunom.", IV; Gregory Nazianzen, "Orat. xxx", p. 20; Basil, "Hom. xvi"; Cyril of Alexandria, "Thesaurus assert.", vi).

We have already adverted to the view that the Son is the Wisdom and Power of the Father in the full and formal sense. This teaching constantly recurs from the time of Origen to that of St. John Damascene (Origen apud Athan., "De decr. Nic.", p. 27; Athanasius, "Con. Arianos", I, p. 19; Cyril of Alexandria, "Thesaurus"; John Damascene, "Fid.orth.", I, xii). It is based on the Platonic philosophy accepted by the Alexandrine School. This differs in a fundamental point from the Aristoteleanism of the Scholastic theologians. In Aristotelean philosophy perfection is always conceived statically. No actlon, transient or immanent, can proceed from any agent unless that agent, as statically conceived, possesses whatever perfection is contained in the action. The Alexandrine standpoint was other than this. To them perfection must be sought in dynamic activity. God, as the supreme perfection, is from all eternity self-moving, ever adorning Himself with His own attributes: they issue from Him and, being Divine, are not accidents, but subsistent realities. To these thinkers, therefore, there was no impossibility in the supposition that God is wise with the Wisdom which is the result of His own immanent action, powerful with the Power which proceeds from Him. The arguments of the Greek Fathers frequently presuppose this philosophy as their bssis; and unless it be clearly grasped, reasoning which on their premises is conclusive will appear to us invalid and fallacious. Thus it is sometimes urged as a reason for rejecting Arianism that, if there were a time when the Son was not, it follows that God must then have been devoid of Wisdom and of Power — a conclusion from which even Arians would shrink.

E. The Holy Spirit

A point which in Western theology gives occasion for some discussion is the question as to why the Third Person of the Blessed Trinity is termed the Holy Spirit. St. Augustine suggests that it is because He proceeds from both the Father and the Son, and hence He rightly receives a name applicable to both (De Trin., xv, n. 37). To the Greek Fathers, who developed the theology of the Spirit in the light of the philosophical principles which we have just noticed, the question presented no difficulty. His name, they held, reveals to us His distinctive character as the Third Person, just as the names Father and Son manifest the distinctive characters of the First and Second Persons (cf. Gregory Thaumaturgus, "Ecth. fid."; Basil, "Ep. ccxiv", 4; Gregory Nazianzen, "Or. xxv", 16). He is autoagiotes, the hypostatic holiness of God, the holiness by which God is holy. Just as the Son is the Wisdom and Power by which God is wise and powerful, so the Spirit is the Holiness by which He is holy. Had there ever been a time, as the Macedonians dared to say, when the Holy Spirit was not, then at that time God would have not been holy (St. Gregory Nazianzen, "Orat. xxxi", 4).

On the other hand, pneuma was often understood in the light of John 10:22 where Christ, appearing to the Apostles, breathed on them and conferred on them the Holy Spirit. He is the breath of Christ (John Damascene, "Fid. orth.", 1, viii), breathed by Him into us, and dwelling in us as the breath of life by which we enjoy the supernatural life of God's children (Cyril of Alexandria, "Thesaurus"; cf. Petav., "De Trin", V, viii). The office of the Holy Spirit in thus elevating us to the supernatural order is, however, conceived in a manner somewhat different from that of Western theologians. According to Western doctrine, God bestows on man sanctifying grace, and consequent on that gift the Three Persons come to his soul. In Greek theology the order is reversed: the Holy Spirit does not come to us because we have received sanctifying grace; but it is through His presence we receive the gift. He is the seal, Himself impressing on us the Divine image. That Divine image is indeed realized in us, but the seal must be present to secure the continued existence of the impression. Apart from Him it is not found (Origen, "In Joan. ii", vi; Didymus, "De Spiritu Sancto", x, 11; Athanasius, "Ep. ad. Serap.", III, iii). This Union with the Holy Spirit constitutes our deification (theopoiesis). Inasmuch as He is the image of Christ, He imprints the likeness of Christ upon us; since Christ is the image of the Father, we too receive the true character of God's children (Athanasius, loc.cit.; Gregory Nazianzen, "Orat. xxxi", 4). It is in reference to this work in our regard that in the Nicaeno-Constantinopolitan Creed the Holy Spirit is termed the Giver of life (zoopoios). In the West we more naturally speak of grace as the life of the soul. But to the Greeks it was the Spirit through whose personal presence we live. Just as God gave natural life to Adam by breathing into his inanimate frame the breath of life, so did Christ give spiritual life to us when He bestowed on us the gift of the Holy Ghost.

The transition to the Latin theology of the Trinity was the work of St. Augustine. Western theologians have never departed from the main lines which he laid down, although in the Golden Age of Scholasticism his system was developed, its details completed, and its terminology perfected. It received its final and classical form from St. Thomas Aquinas. But it is necessary first to indicate in what consisted the transition effected by St. Augustine. This may be summed up in three points:

He views the Divine Nature as prior to the Personalities. Deus is for him not God the Father,but the Trinity. This was a step of the first importance, safeguarding as it did alike the unity of God and the equality of the Persons in a manner which the Greek system could never do. As we have seen, one at least of the Greeks, Didymus, had adopted this standpoint and it is possible that Augustine may have derived this method of viewing the mystery from him. But to make it the basis for the whole treatment of the doctrine was the work of Augustine's genius.

He insists that every external operation God is due to the whole Trinity, and cannot be attributed to one Person alone, save by appropriation (see ). The Greek Fathers had, as we have seen, been led to affirm that the action (energeia) of the Three Persons was one, and one alone. But the doctrine of appropriation was unknown to them, and thus the value of this conclusion was obscured by a traditional theology implying the distinct activities of Father, Son, and Holy Spirit.

By indicating the analogy between the two processions within the Godhead and the internal acts of thought and will in the human mind (De Trin., IX, iii, 3; X, xi, 17), he became the founder of the psychological theory of the Trinity, which, with a very few exceptions, was accepted by every subsequent Latin writer.

In the following exposition of the Latin doctrines, we shall follow St. Thomas Aquinas, whose treatment of the doctrine is now universally accepted by Catholic theologians. It should be observed, however, that this is not the only form in which the psychological theory has been proposed. Thus Richard of St. Victor, Alexander of Hales, and St. Bonaventure, while adhering in the main to Western tradition, were more influenced by Greek thought, and give us a system differing somewhat from that of St. Thomas.

A. The Son

Among the terms empIoyed in Scripture to designate the Second Person of the Blessed Trinity is the Word (John 1:1). This is understood by St. Thomas of the Verbum mentale, or intellectual concept. As applied to the Son, the name, he holds, signifies that He proceeds from the Father as the term of an intellectual procession, in a manner analogous to that in which a concept is generated by the human mind in all acts of natural knowledge. It is, indeed, of faith that the Son proceeds from the Father by a veritable generation. He is, says the Nicaeno-Constantinopolitan Creed, begotten before all worlds". But the Procession of a Divine Person as the term of the act by which God knows His own nature is rightly called generation. This may be readily shown. As an act of intellectual conception, it necessarily produces the likeness of the object known. And further, being Divine action, it is not an accidental act resulting in a term, itself a mere accident, but the act is the very substance of the Divinity, and the term is likewise substantial. A process tending necessarily to the production of a substantial term like in nature to the Person from Whom it proceeds is a process of generation. In regard to this view as to the procession of the Son, a difficulty was felt by St. Anselm (Monol., lxiv) on the score that it would seem to involve that each of the Three Persons must needs generate a subsistent Word. Since all the Powers possess the same mind, does it not follow, he asked, that in each case thought produces a similar term? This difficulty St. Thomas succeeds in removing. According to his psychology the formation of a concept is not essential to thought as such, though absolutely requisite to all natural human knowledge. There is, therefore, no ground in reason, apart from revelation, for holding that the Divine intellect produces a Verbum mentale. It is the testimony of Scripture alone which tells us that the Father has from all eternity begotten His consubstantial Word. But neither reason nor revelation suggests it in the case of the Second and Third Persons (I:34:1, ad 3).

Not a few writers of great weight hold that there is sufficient consensus among the Fathers and Scholastic theologians as to the meaning of the names Word and Wisdom (Proverbs 8), applied to the Son, for us to regard the intellectual procession of the Second Person as at least theologically certain, if not a revealed truth (cf. Suarez, "De Trin.", I, v, p. 4; Petav., VI, i, 7; Franzelin, "De Trin.", Thesis xxvi). This, however, seems to be an exaggeration. The immense majority of the Greek Fathers, as we have already noticed, interpret logos of the spoken word, and consider the significance of the name to lie not in any teaching as to intellectual procession, but in the fact that it implies a mode of generation devoid of all passion. Nor is the tradition as to the interpretation of Proverbs 8, in any sense unanimous. In view of these facts the opinion of those theologians seems the sounder who regard this explanation of the procession simply as a theological opinion of great probability and harmonizing well with revealed truth.

B. The Holy Spirit

Just as the Son proceeds as the term of the immanent act of the intellect, so does the Holy Spirit proceed as the term of the act of the Divine will. In human love, as St. Thomas teaches (I:27:3), even though the object be external to us, yet the immanent act of love arouses in the soul a state of ardour which is, as it were, an impression of the thing loved. In virtue of this the object of love is present to our affections, much as, by means of the concept, the object of thought is present to our intellect. This experience is the term of the internal act. The Holy Spirit, it is contended, proceeds from the Father and the Son as the term of the love by which God loves Himself. He is not the love of God in the sense of being Himself formally the love by which God loves; but in loving Himself God breathes forth this subsistent term. He is Hypostatic Love. Here, however, it is necessary to safeguard a point of revealed doctrine. It is of faith that the procession of the Holy Spirit is not generation. The Son is "the only begotten of the Father" (John 1:14). And the Athanasian Creed expressly lays it down that the Holy Ghost is "from the Father and the Son, neither made, nor created, nor begotten, but proceeding." If the immanent act of the intellect is rightly termed generation, on what grounds can that name be denied to the act of the will? The answers given in reply to this difficulty by St. Thomas, Richard of St. Victor, and Alexander of Hales are very different. It will be sufficient here to note St. Thomas's solution. Intellectual procession, he says, is of its very nature the production of a term in the likeness of the thing conceived. This is not so in regard to the act of the will. Here the primary result is simply to attract the subject to the object of his love. This difference in the acts explains why the name generation is applicable only to the act of the intellect. Generation is essentially the production of like by like. And no process which is not essentially of that character can claim the name.

The doctrine of the procession of the Holy Spirit by means of the act of the Divine will is due entirely to Augustine. It is nowhere found among the Greeks, who simply declare the procession of the Spirit to be beyond our comprehension, nor is it found in the Latins before his time. He mentions the opinion with favour in the "De fide et symbolo" (A.D. 393); and in the "De Trinitate" (A.D. 415) develops it at length. His teaching was accepted by the West. The Scholastics seek for Scriptural support for it in the name Holy Spirit. This must, they argue, be, like the names Father and Son, a name expressive of a relation within the Godhead proper to the Person who bears it. Now the attribute holy, as applied to person or thing, signifies that the being of which it is affirmed is devoted to God. It follows therefore that, when applied to a Divine Person as designating the relation uniting Him to the other Persons, it must signify that the procession determining His origin is one which of its nature involves devotion to God. But that by which any person is devoted to God is love. The argument is ingenious, but hardly convincing; and the same may be said of a somewhat similar piece of reasoning regarding the name Spirit (I:36:1). The Latin theory is a noble effort of the human reason to penetrate the verities which revelation has left veiled in mystery. It harmonizes, as we have said, with all the truths of faith. It is admirably adapted to assist us to a fuller comprehension of the fundamental doctrine of the Christian religion. But more than this must not be claimed. It does not possess the sanction of revelation.

C. The Divine Relations

The existence of relations in the Godhead may be immediately inferred from the doctrine of processions, and as such is a truth of Revelation. Where there is a real procession the principle and the term are really related. Hence, both the generation of the Son and the procession of the Holy Spirit must involve the existence of real and objective relations. This part of Trinitarian doctrine was familiar to the Greek Fathers. In answer to the Eunomian objection, that consubstantiality rendered any distinction between the Persons impossible, Gregory of Nyssa replies: "Though we hold that the nature [in the Three Persons] is not different, we do not deny the difference arising in regard of the source and that which proceeds from the source [ten katato aition kai to aitiaton diaphoran]; but in this alone do we admit that one Person differs from another" ("Quod non sunt tres dii"; cf. Gregory Nazianzen, "Or. theol.", V, ix; John Damascene, "F.O.", I, viii). Augustine insists that of the ten Aristotelean categories two, stance and relation, are found in God ("De Trin.", V, v). But it was at the hands the Scholastic theologians that the question received its full development. The results to which they led, though not to be reckoned as part of the dogma, were found to throw great light upon the mystery, and to be of vast service in the objections urged against it.

From the fact that there are two processions in Godhead, each involving both a principle and term, it follows that there must be four relations, two origination (paternitas and spiratio) and two of procession (filiatio and processio). These relations are what constitute the distinction between the Persons. They cannot be digtinguished by any absolute attribute, for every absolute attribute must belong to the infinite Divine Nature and this is common to the Three Persons. Whatever distinction there is must be in the relations alone. This conclusion is held as absolutely certain by all theologians. Equivalently contained in the words of St. Gregory of Nyssa, it was clearly enunciated by St. Anselm ("De process. Sp. S.", ii) and received ecclesiastical sanction in the "Decretum pro Jacobitis" in the form: "[In divinis] omnia sunt unum ubi non obviat relationis oppositio." Since this is so, it is manifest that the four relations suppose but Three Persons. For there is no relative opposition between spiration on the one hand and either paternity or filiation on the other. Hence the attribute of spiration is found in conjunction with each of these, and in virtue of it they are each distinguished from procession. As they share one and the same Divine Nature, so they possess the same virtus spirationis, and thus constitute a single originating principle of the Holy Spirit.

Inasmuch as the relations, and they alone, are distinct realities in the Godhead, it follows that the Divine Persons are none other than these relations. The Father is the Divine Paternity, the Son the Divine Filiation, the Holy Spirit the Divine Procession. Here it must be borne in mind that the relations are not mere accidental determinations as these abstract terms might suggest. Whatever is in God must needs be subsistent. He is the Supreme Substance, transcending the divisions of the Aristotelean categories. Hence, at one and the same time He is both substance and relation. (How it is that there should be in God real relations, though it is altogether impossible that quantity or quality should be found in Him, is a question involving a discussion regarding the metaphysics of relations, which would be out of place in an article such as the present.)

It will be seen that the doctrine of the Divine relations provides an answer to the objection that the dogma of the Trinity involves the falsity of the axiom that things which are identical with the same thing are identical one with another. We reply that the axiom is perfectly true in regard to absolute entities, to which alone it refers. But in the dogma of the Trinity when we affirm that the Father and Son are alike identical with the Divine Essence, we are affirming that the Supreme Infinite Substance is identical not with two absolute entities, but with each of two relations. These relations, in virtue of their nature as correlatives, are necessarily opposed the one to the other and therefore different. Again it is said that if there are Three Persons in the Godhead none can be infinite, for each must lack something which the others possess. We reply that a relation, viewed precisely as such, is not, like quantity or quality, an intrinsic perfection. When we affirm again it is relation of anything, we affirm that it regards something other than itself. The whole perfection of the Godhead is contained in the one infinite Divine Essence. The Father is that Essence as it eternally regards the Son and the Spirit; the Son is that Essence as it eternally regards the Father and the Spirit; the Holy Spirit is that Essence as it eternally regards the Father and the Son. But the eternal regard by which each of the Three Persons is constituted is not an addition to the infinite perfection of the Godhead.

The theory of relations also indicates the solution to the difficulty now most frequently proposed by anti-Trinitarians. It is urged that since there are Three Persons there must be three self-consciousnesses: but the Divine mind ex hypothesi is one, and therefore can possess but one self-consciousness; in other words, the dogma contains an irreconcilable contradiction. This whole objection rests on a petitio principii: for it takes for granted the identification of person and of mind with self-consciousness. This identification is rejected by Catholic philosophers as altogether misleading. Neither person nor mind is self-consciousness; though a person must needs possess self-consciousness, and consciousness attests the existence of mind (see ). Granted that in the infinite mind, in which the categories are transcended, there are three relations which are subsistent realities, distinguished one from another in virtue of their relative opposition then it will follow that the same mind will have a three-fold consciousness, knowing itself in three ways in accordance with its three modes of existence. It is impossible to establish that, in regard of the infinite mind, such a supposition involves a contradiction.

The question was raised by the Scholastics: In what sense are we to understand the Divine act of generation? As we conceive things, the relations of paternity and filiation are due to an act by which the Father generates the Son; the relations of spiration and procession, to an act by which Father and Son breathe forth the Holy Spirit. St. Thomas replies that the acts are identical with the relations of generation and spiration; only the mode of expression on our part is different (I:41:3, ad 2). This is due to the fact that the forms alike of our thought and our language are moulded upon the material world in which we live. In this world origination is in every case due to the effecting of a change. We call the effecting of the change action, and its reception passion. Thus, action and passion are different from the permanent relations consequent on them. But in the Godhead origination is eternal: it is not the result of change. Hence the term signifying action denotes not the production of the relation, but purely the relation of the Originator to the Originated. The terminology is unavoidable because the limitations of our experience force us to represent this relation as due to an act. Indeed throughout this whole subject we are hampered by the imperfection of human language as an instrument wherewith to express verities higher than the facts of the world. When, for instance, we say that the Son possesses filiation and spiration the terms seem to suggest that these are forms inherent in Him as in a subject. We know, indeed, that in the Divine Persons there can be no composition: they are absolutely simple. Yet we are forced to speak thus: for the one Personality, not withstanding its simplicity, is related to both the others, and by different relations. We cannot express this save by attributing to Him filiation and spiration (I:32:2).

D. Divine Mission

It has been seen that every action of God in regard of the created world proceeds from the Three Persons indifferently. In what sense, then, are we to understand such texts as "God sent . . . his Son into the world" (John 3:17), and "the Paraclete cometh, whom I will send you from the Father" (John 15:26)? What is meant by the mission of the Son and of the Holy Spirit? To this it is answered that mission supposes two conditions:

That the person sent should in some way proceed from the sender and

that the person sent should come to be at the place indicated.

The procession, however, may take place in various ways — by command, or counsel, or even origination. Thus we say that a king sends a messenger, and that a tree sends forth buds. The second condition, too, is satisfied either if the person sent comes to be somewhere where previously he was not, or if, although he was already there, he comes to be there in a new manner. Though God the Son was already present in the world by reason of His Godhead, His Incarnation made Him present there in a new way. In virtue of this new presence and of His procession from the Father, He is rightly said to have been sent into the world. So, too, in regard to the mission of the Holy Spirit. The gift of grace renders the Blessed Trinity present to the soul in a new manner: that is, as the object of direct, though inchoative, knowledge and as the object of experimental love. By reason of this new mode of presence common to the whole Trinity, the Second and the Third Persons, inasmuch as each receives the Divine Nature by means of a procession, may be said to be sent into the soul. (See also ; ; ; .) Among the numerous patristic works on this subject, the following call for special mention: ST. ATHANASIUS, Orationes quatuor contra Arianos; IDEM, Liber de Trinitate et Spiritu Sancto; ST. GREGORY NAZIANZEN, Orationes V de theologia; DIDYMUS ALEX., Libri III de Trinitate; IDEM, Liber de Spir. Sancto; ST. HILARY OF POITIERS, Libri XII de Trinitate; ST. AUGUSTINE, Libri XV de Trinitate; ST. JOHN DAMASCENE, Liber de Trinitate; IDEM, De fide orthodoxa, I.